pwru is one of the best tools for troubleshooting Linux network issues. The full name of pwru is Packet Where Are You?,How does it work?eBPF allows us to attach hooks to kernel functions. When a kernel function is executed, eBPF can define additional actions, such as recording the function and its parameters and then printing them out.When Linux starts, it generates /proc/kallsyms, a file that pwru reads to locate all functions related to skb (the data structure for network packets in the kernel). Then, pwru hooks into these functions. This allows eBPF to track the exact path a packet takes th...